【摘要】 在全球气候变化背景下,该研究分析了缙云山针阔混交林能量通量在不同时间尺度的动态特征及其对环境因子的响应。该研究选取缙云山针阔混交林为研究区域,基于涡度相关法测得的数据,使用相关性因子分析和结构方程模型分析缙云山针阔混交林2020、2021和2023年(2022年数据缺失)的长时间序列的通量数据。主要结论:(1)净辐射(Rn)、显热通量(H)和潜热通量(LE)在日尺度上呈现出单峰型趋势,峰值分别出现于14:00时,并于19:00后趋近于0;而土壤热通量(G)呈双峰模式,日最低值出现于日出前,最高值出现于14:00时。(2)在月份尺度上, Rn对能量通量的驱动效应自4月起增强, 7–8月达峰值,随后逐渐减弱;冠层导度(Gs)对LE的限制呈同步趋势。(3)在生长季尺度上, Rn是能量通量变化的主要影响因子,从相关因子判断Gs对H有轻微限制作用,而对LE有明显限制作用,但其实植物的水分平衡机制影响最大能量。(4) 3年的年均波文比(β)分别为0.69、0.63和0.76。(5)受极端干旱影响,该地区年尺度H出现双峰型趋势。该研究通过对缙云山针阔混交林能量通量特征与影响因子进行分析,揭示了能量通量的动态变化过程,量化了环境因子的影响,为评估亚热带森林生态系统对气候变化的响应和森林保育提供了科学依据。更多还原

【Abstract】 Aims Under the background of global climate change, this study investigated the dynamic characteristics of energy fluxes in Jinyun Mountain’s coniferous-broadleaf mixed forest across different temporal scales and their responses to environmental factors. Methods We selected the mixed coniferous and broadleaf forests in Jinyun Mountains as the study area, and analyzed the long time series flux data of the mixed coniferous and broadleaf forests in Jinyun Mountains for the years 2020, 2021, and 2023(data for 2022 are missing) using correlation factor analysis and structural equation modeling based on the data measured by eddy correlation technique. Important findings(1) At the diurnal scale, net radiation(Rn), sensible heat flux(H), and latent heat flux(LE) exhibited unimodal trends, with their peak values occurring at 14:00 local time, and approaching near-zero values after 19:00. In contrast, soil heat flux(G) displayed a bimodal pattern, reaching its daily minimum prior to sunrise and attaining its daily maximum at 14:00 local time.(2) At the monthly scale, the influence of Rn on energy fluxes increased from April, reached its maximum in July and August, then gradually decreased. The influence of canopy conductance(Gs) on LE followed the same trend.(3) At the growing season scale, Rn was the primary influencing factor for energy flux variations. Correlation factor analysis indicated that Gs had a slight limiting effect on H but a significant limiting effect on LE. However, the plant water balance mechanism exerted the strongest influence.(4) The annual mean Bowen ratios(β) for the three years were 0.69, 0.63, and 0.76, respectively.(5) Influenced by extreme drought, the sensible heat flux at the annual scale exhibited a bimodal trend. This study analyzed the characteristics and influencing factors of energy fluxes in the Jinyun Mountain coniferous-broadleaf mixed forests, revealing the dynamic processes of energy fluxes, quantifying the impacts of environmental factors, and providing a scientific basis for assessing the response of subtropical forest ecosystems to climate change and forest conservation.更多还原